How to rename instanced objects in animation nodes?
This question is now moot but I'm not sure how to close it.
I believe that the problem I was experiencing here was due to using the AN+EN build for 2.83 LTS with Blender 2.90.1 instead.
I resolved my Cycles material issue in 2.90.1 with a simple script:
materialIn.node_tree.nodes[&quot;Principled BSDF&quot;].inputs[17].default_value = newColor
materialOut = materialIn

and now I'm just using the latest AN and EN in 2.90.1, without a lot of crashes.